A spark arrestor is a generic term used to describe a device that is intended to prevent combustible materials, such as sparks, from escaping into areas that could result in ignition and fire. The most recognized spark arrestors are those wire mesh devices used as chimney caps on chimneys or vent pipes for fireplaces and wood stoves in houses and buildings. By contrast, flame arrestors, such as those devices that are an integral part of a muffler assembly of an “off the road” vehicle, are used to prevent flames from escaping the mufflers and causing fires.
With the advent of more stringent air pollution control requirements for many industries, bag houses containing fabric filters are typically the devices of choice for capturing particulate matter. However, industrial applications that produce air-borne sparks as well as dust and particulates cannot use bag houses or fabric filter materials due to the potential for fabric filter fires without the use of an effective spark arresting device. Spark arresting devices that have been used with limited success, depending on the gas flow volumes and particles sizes have included drop out boxes, baffles, wire mesh, submerged dip tubes, cyclone separators, multi-cyclone separators, and sensors for activating water sprays. However, sensors and water spray systems are not 100 percent effective and often fail due to a variety of factors including misalignment, dirt build up, corrosion, or other causes.
Despite the variety of devices currently available, there continues to be a need for a spark arrestor that is effective to meet certain critical design criteria for industrial applications where fires and explosions cannot be tolerated and where there must be minimum downtime for the spark arrestor and dust collection system. Industries that may generate sparks that could cause fire or explosions, include, but are not limited to metal foundries for metal reclaiming and processing including high temperature melt lines, metal shredding, metal grinding, metal welding, and polishing of metal parts; fiber and particleboard including processing of the fiber and the particleboard as well as sawing and sanding of finished board; chemical industries that use spray dryers and the pneumatic conveying of the various dusts and powders; food processing industries such as coffee, chocolate, tobacco drying, spice and seasoning grinding, and the pneumatic conveying of powdered food products. Also included are all types of industrial combustion sources.